The present invention relates to an articulation or joint, especially for connecting sidepieces of a multi-purpose ladder that can be folded up.
DE 32 11 164 C2 describes a multi-purpose ladder that can be folded together, the sidepieces of which are connected by joints or articulations that are disposed in pairs and can be locked in a number of working positions. Each of these joints has two joint portions that are pivotable about a common joint shaft, whereby one of these joint portions forms a dual-shell locking disk. In the vicinity of its periphery, this locking disk has grooves that are distributed in conformity with the operating positions. Engaging into this grooves is a spring-loaded locking piece that can be raised out of the grooves for the purpose of pivoting the joint portions. This locking piece comprises a locking bar having an essentially rectangular cross-sectional configuration; the height of the locking bar is approximately equal to the width of the second joint portion. The locking piece is guided in a recessed portion in the side walls of the second joint portion, and includes a guide part that adjoins the locking bar, with the height of the guide bar being only slightly less than the height of the second joint portion, whereby the width is greater than the width of the recessed portion. In order to return the locking piece into the locking position, an abutment is provided for the return spring. The locking piece can be raised out of the respective groove of the locking disk by means of a release lever that is pivotably mounted on the second joint portion and is connected with an actuating lever. The release levers of the joints associated with the two sidepieces are interconnected by a rod, so that an unlocking of the locking pieces of the paired joints can be simultaneously activated. The recessed portion has sections of different width, so that a deposition surface is formed in which the locking bar is held in its disengaged position. The locking disk, which is provided with grooves, is provided with projections disposed next to the grooves that serve as abutment surfaces for the locking bar of the locking piece, so that the locking piece is pressed from the deposition surface in the direction of folding-together of the sidepieces, and hence automatically engages in the groove.
It is an object of the present invention to provide a joint or articulation that has a straightforward construction and is economical to produce.